Movable jaw chucking device



April 29, 1952 G. SANDERSON MOVABLE JAW CHUCKING DEVICE 2 SHEETS-SHEET 1 Filed May 23, 1947 H15 ATTORNEY.

April 29, 1952 G. SANDERSON 2,594,503

MOVABLE JAW cnucxmc DEVICE Filed May 23, 1947 2 SHEETS-SHEET 2 INVENTORZ yaw/me 544/05650/14 M Hl5 ATTORNEY.

Patented Apr. 29, 1952 MOVABLE J AW CHUCKING DEVICE Gunnar Sanderson, McKeesport, Pa., assignor to United States Steel Company, a corporation of New Jersey Application May 23, 1947, Serial No. 749,983

This invention relates to the helical reduction of rounds in a seamless tube piercing mill and more particularly to reducing rounds in the first pie'rcer of a seamless tube piercing mill comprising first and second piercers.

In order to reduce the number .of sizes of rounds or billets which must be stocked in order to manufacture a full range of pipe sizes, it is proposed to helically reduce the diameter of rounds in. the first piercer and single pierce the so-reduced rounds in the second piercer. Such reducing is entirely feasible but on conventional mills. there is no way of moving the reduced billet away from the mill so that it can be discharged from the outlet trough onto the skidway interposed between the outlet trough of the first piercer and the inlet trough of the second piercer. In conventional piercing the pierced billet is rolled over a mandrel plug held intermediate the rolls onthe compression mandrel bar which carries the plug on its forward end. At the completion of the rolling operationythe mandrel bar with the telescoped pierced billet is withdrawn from the metal working position to strip the pierced billet therefrom. In so doing, the pierced billet iscarried withthe mandrel bar afiiced distance, so that the trailing end will clear the mill and the billet will be properly positioned to be lifted from the trough by kick-off arms or other elevating devices onto the skidway. However, when the billet is merely reduced and not pierced, it is accordingly not telescoped over. the mandrel bar and therefore cannot be retracted so as to clear the mill by withdrawing the mandrel bar from the interior thereof.

It is accordingly an object of the present invention to provide a method of and means for permitting the reducing of billets in a piercing mill.

It is a further object to provide a billet gripping device on the forward end of a compression mandrel bar.

The foregoing and further objects will be apparent from the following specification when read in conjunction with the attached drawings, wherein:

Figure l is a diagrammatic plan of a seamless tube piercing mill comprising two piercers;

Figure 2 is a plan of the outlet side of the first piercer;

Figure 3 is an elevation of the mandrel bar and thrust block;

Figure 4 is an enlarged elevation of the gripping device of my invention;

Figure 5 is an elevation of the forward end of 3 Claims. (Cl. 279-4) the gripper in a differently adjusted position; and

Figure 6 is a cross-sectional elevation on lines VI -VI of Figure 4. v

Referring more particularly to the drawingsi there is shown diagrammatically in Figure 1 a conventional double-piercer layout composed of first piercer 2, outlet trough 4, mandrel bar carriage 6 and skidway 8 for transferring a-pierced billet from the trough 4 to the inlet trough ill of the second piercer l2.

As is shown in Figure 2, the mandrel bar carriage 6 carries a compression mandrel bar [4, which is adapted to be reciprocated by a cable l6. connected to the block and mounted around pulleys l8, one of which is driven by a motor 20.

The forward end of the mandrel bar I4 is interiorly thraded as at 22 to conventionally receive a bar cap on which the piercing point is disposed. "I-Iowever, in accordance with th teach.-

ings of my invention, the bar cap is removed and replaced by gripper 24. The support member of the gripper is a tubular member26, which is exteriorly threaded at its rearward end and adapted to be screwed into the interior threads 22 of 'the mandrel bar. Rigidly mounted on the tubular member 26 is a rearward bracket 28 and forward bracket 30, both of which are preferably bifurcated. The forward bracket 3|] has a plurality of vertically spaced holes 32 therethrough for pivotally mounting a jaw member 34 having a right angularly disposed upstanding arm 36. The underside of the outer end of the jaw mem ber 34 is preferably convex in longitudinal section and serrated as at 38.

A double-acting cylinder 40 is pivotally mounted on the rearward bracket 28 by means of trunnions 42 which are disposed in slots 44 in the bifurcated upper end of the bracket 28. Disposed in the cylinder is a piston 45 having a forwardly extending rod 48, the outer end of which is bifurcated and pivotally connected to the arm 36. The piston may be suitably actuated by operation of a 1-way valve 49 to admit air under pressure to one end of the cylinder and exhaust it from the other end. Thus, by admitting compressed air to the rearward end of the cylinder, the piston will be moved forwardly and thereby cause the jaw 34 to move downwardly into gripping position to grip a workpiece W between the surfaces 38 and serrated surfaces 50 of a lower jaw 52 suitably connected, such as by threading, to the forward end of the support member 26. It is noted that the gripper can be accommodated to a wide variety of billet sizes by mounting the jaw 34 in upper or lower holes 32.

From the foregoing, it is seen that I have provided an arrangement for conveniently retracting reduced billets from a piercing mill which utilizes the same mandrel bar and equipment ordinarily used for holding a piercing point between the rolls and stripping the telescoped workpiece therefrom.

While I have shown and described one specific embodiment of my invention, it will be understood that this embodiment is merely for the purpose of illustration and description and that various other forms may be devised within the scope of my invention, as defined in the appended claims.

I claim:

1. A device for handling bar material comprising a gripping member mounted for reciprocating movement, said gripping member comprising an elongated support, a lower jaw member on the forward end of said support, said jaw member having serrated gripping surfaces on the upper side thereof, vertically disposed forward and rearward bifurcated brackets on said support, said forward bracket having a plurality of vertically spaced holes therethrough, a jaw member adapted to be adjustably mounted by a pin member disposed in certain of said holes, said jaw member having a convex serrated gripping surface disposed above the serrated surfaces of said lower jaw member, said upper jaw member having an upwardly extending arm rigidly connected thereto, a double-acting hydraulic cylinder having trunnions on its sides, said trunnions being disposed on the bifurcated sides of said rearward bracket, a piston in said cylinder, and a piston rod connecting said piston to the upwardly extending arm on said upper jaw member.

2. A device for handling bar material comprising a gripping member mounted for reciprocable movement, said gripping member comprising an elongated support, a lower jaw member on the forward end of said support, said jaw member having serrated gripping surfaces on the upper side thereof, vertically disposed forward and rearward bifurcated brackets on said support, an upper jaw member pivotally mounted on said forward bracket, said jaw member having a convex serrated gripping surface disposed above the serrated surfaces of said lower jaw member, said upper jaw member having a vertically extending arm rigidly connected thereto, a doubleacting hydraulic cylinder having trunnions on its sides, said trunnions being disposed on the bifurcated sides of said rearward bracket, a piston in said cylinder and a piston rod connecting said piston to the arm on said upper jaw member.

3. A device for handling bar material comprising a gripping member mounted for reciprocable movement, said gripping member comprising an elongated support, a lower jaw mounted on the forward end of said support, vertically disposed forward and rearward bifurcated brackets on said support, an upper jaw member pivotally mounted on said forward bracket, said upper jaw member having a vertically extending arm rigidly connected thereto, a double-acting hydraulic cylinder having trunnions on its sides, said trunnions being disposed on the rearward bifurcated bracket, a piston in said cylinder and a piston rod connecting said piston to the vertically extending arm on said upper jaw member.

GUNNAR SANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

